S-(N-methyl-N-phenyl-carbamoylmethyl) esters of certain thiophosphonic and dithiophosphonic acids

ABSTRACT

Compounds of the formula   wherein R is alkyl of 1 to 4 carbon atoms, and X is oxygen or sulfur; THE COMPOUNDS ARE USEFUL AS HERBICIDES.

United States Patent 11 1 [111 3,903,204

Sehring et al. 1 Sept. 2, 1975 S-(N-METHYL-N-PHENYL- 335L679 11/1967SZLIbO et al. 260/943 3,717,690 3 1973 Newman 71/87 CARBAMOYLMETHYL)ESTERS OF CERTAIN THIOPHOSPHONIC AND DITHIOPHOSPHONIC ACIDS inventors:Richard Sehring; Wolfgang Buck;

Gerbert Linden, all of lngelheim am Rhein, Germany Assignee: CelamerckGmbH & Co. KG,

Ingelheim am Rhein. Germany Filed: Apr. 11, 1974 Appl. No; 460,154

Foreign Application Priority Data Apr. 21. 1973 Germany 2320371 U.S. Cl.260/943; 71/87; 260/972 Int. Cl. C071 9/40 Field of Search 260/943;71/87 References Cited UNITED STATES PATENTS 8/1963 Speziale ct al260/943 X OTHER PUBLICATIONS Fine Chemical Patents Journal, Vol. 6. No.48, 12-- 2-1966. British, 5: Gen. Org., p. 7.

Primary Examiner-Lorraine A. Weinberger Assistant E.\'aminerRichard L.Raymond Attorney, Agent, or Firm-Hammond & Littcll [57] ABSTRACTCompounds of the formula wherein R is alkyl of l to 4 carbon atoms, andX is oxygen or sulfur;

the compounds are useful as herbicides.

10 Claims, No Drawings S-(N-METHYL-N-PHENY'L CARBAMOYLMETHYL) ESTERS OFCERTAIN THIOPHOSPHONIC AND DITHIOPHOSPHONIC ACIDS This invention relates'to novel S-(Nmcthyl-N- phenyl-earbamoylmethyl)O-alkyl-chloromethyl-thiophosphonatesalkyl-chloromethyl-thiophosphonates and -dithiophosphonates, as well asto a method of preparing these compounds.

More particularly, the present invention relates to a novel class ofthiophosphonic and dithiophosphonic acid esters represented by theformula cicH x P CH,

wherein R is alkyl of l to 4 carbon atoms, and

X is oxygen or sulfur.

The compounds of the formula l may be prepared by reacting an O-loweralkyl chloromethylphosphonatc or thiophosphonate chloride of the formula(Ill) Ro wherein R and X have the same meanings as in formula I, with athioglycolic acid N-methyl-anilide of the formula WhenX informula-lll'is sulfur, the reaction may also be carried out in. water oran aqueous solvent.

The starting compounds may be prepared by known methods For instance, acompound of the formula III isobtained by reacting achloromethyl-phosphonic acid or -thiophosphonic acid dichloride with alower alkanol of the formula i a W ROH V wherein Rhas the meaningspreviously defined, in the presence ofa base (see Houbemweyl 12/1, 417et seq.

and 560 etseq. t

A compound of the formula lV may.be prepared from chloroacetic acid,N-rnethyl-aniline and, ammonium thiocyanate pursuant to the methoddescribed in J. Prakt. Chem. 153, 68 (1939).

The end products of the present invention are obtained in pure form andwith good yields; they are yellowish oils which cannotbe distilledwithout decomposition. The raw products may be purifiedby extraction ofa solution thereof in a suitable solvent with dilute sodium hydroxide ora dilute acid and water, followed by evaporation of the solution invacuo. The proof of purity is effected by means of thin-layerchromatography (on silicagel plates; flow agent: Heptan/acetone 2:l Thepurified compounds are characterized by elemental analysis andrefraction indeces; their NMR- and IR- spectra confirm the indicatedstructural formula.

The following examples illustrate the present invention and will enableothers skilled in the art to understand it more completely. It should beunderstood, however, that the invention is not limited solely to theparticular examples given below.

EXAMPLE 1 S-(N-Methyl-N-phenyl-carbarnoylmethylO-ethyl-chl'oromethyldithiophosphonate 193.5 gm 1 mol) of O-ethylchloromethyl-thiophos phonate chloride and 183.0 gm (1 mol) ofthioglycolic acid N-methyl-anilide were dissolved in 1 liter of benzene,and 101 gm 1 mol) of triethylamine were added dropwise to the solutionat room temperature over a period of one hour. The resulting mixture wasthen stirred for two hours at 40C. Thereafter, the reaction solution wasstirred twice with 300 ml of water each, then extracted with 200 ml oflNsodium hydroxide, dried with sodium sulfate and evaporated in vacuo,yielding 330 gm (98% of theory) of a yellowish oil having a refractiveindex m3" F 1.5889, which was identi tied to be the compound of theformula cici s P CH,

EXAMPLE 2 S-(NMethyl-N-phenyl-carbamoylmethyl)O-n-butyl-chloromethyl-thiophosphonate 7.7 gm (0.0375 mol) ofO-n-butyl-chloromethylphosphonate chloride and 6.8 gm (0.0375 mol) ofthioglycolicv acid Nme,thyl-anilide were dissolved in 200 ml of benzene,and a solution of 3.8 gm of triethylamine (0.0375 mol) in 15 ml ofbenzene was added dropwise thereto at about 25C. The resulting mixturewas stirred for four hours at room temperature, the precipitatedtriethylamine hydrochloride was separated by vacuum filtration, and thefiltrate was evaporated in vacuo, leaving 13.3 gm 100% of theory) of alight yellow oil having a refractive index n 1.5493, which wasidentified to be the compound of the formula ClCH o v i l n c,a,,-o s ea(to-ru our Analysis: Calculated z C- t8. 2 lei-6.0l%; N-4.01%; c1-10.16%. Found; 048.18%; l-l-5.97%; N-4.15%; Cl- 9.37%.

1.5704, of the formula EXAMPLE 3 Using a procedure analogous'to thatdescribed in EX- ample l S-(N methyl-Nphenyl carbamoylrnethyl) methylchloromethyl-dithiophosph on'ate; "m; 1.6043, Of the formula i 1 cu o scH. co N c.,H,-,

wasprepared from O-methyl chloromethyl-thiophosphonate chloride andthioglycolic acid N-methylanilide.

EXAMPLE 4 Using a procedure= analogous to that described in Example 2,,S-(N-methyl-N-phenyl-earbamoylmethyl) O- n-butyl-chloromethyl-dithiophosphonate, n

isopropyl-chloromethyl-dithiophosphonate, n,, 1 .5783, of the formula(CH CHO SCH. ,CO N CH was prepared fromO-isopropyl-chloromethyl-thiophosphonate chloride and thioglycolie acidN-methylanilide. H

EXAMPLE 6 Using a procedure analogous to'that described'inExample l SN-methyl-N-phenyl-carbamoylmethyl) O-n-propyl-chloromethyl-dithiophosphonate, n f

"1.5760, of'the formula was prepared fromO-npropyl-chloromethyl-thiophosphonate chloride and thioglycolic acidN-methylanilide. 1

EXAMPLE 7 Using a procedure analogous to that described in ExampleS-(N-methyl-N-phenyl-carbamoylmethyl) O- ethyl-chloromethylthiophosphonate, n lf. 420,-of the formula a was prepared from O ethylchloromethyl-phosphonate .chlorideand thioglycolic acid N mthyl-anilideEXAMPL S.

Using a procedure analogous'to that'described in Example 2,S-(N-methylN-phenyl carbamoylmethyl) O secfbutyl ehloromethyl-thiophosphonate; n

1.5470, of the formula P CH3 was prepared from O-sec.butylchloromethylphosph on'ate chloride and thioglycolic acidN-methylanilid'e. v EXAMPLE 9 Using a procedure analogous to thatdescribed in Example 2, S-( N-methyl-N-phenyl-carbamoylmethyl) O-isobutyl-chloromethyl-thiophosphonate, n 1.5471,

of the formula r Clea; y no I P CH,,

was prepared from O-isobutyl chloromethyl- -40 phosphonate chloride andthioglycolic acid N-methylcompounds of present invention, that is, thoseembraced by formula I above, have useful properties. More particularly,the compounds of this invention are effective. agricultural, herbicides,especially against such weeds asamaranth, port ulaea, eleus'in e,digitaria, .alopecurus, chinocloa, veronica, echinocloa, galiurn andvarious .grassy weeds such as millet, while being free from phytotoxicity toward such useful plants as rice, wheat, beets andthellike. I v I For instance, .when thegend product of Ekample l wasapplied .at ,the.rate of 1.5 kg per hectareto a rice field ..three' daysafter s eeding,,the rice plants were unaffected, whereas, various grassyweeds and chinocloa were 100%.eradicated and 97.5% eradication ofamaplants remained-unaffected.

ranth was achieved.

When the end product of Example 6 was applied to a rice field at therate of 1;.5 kg/hectare ten days after emergence of the rice plants, a97.5 to 100% herbicidal effect was obtained against amaranth, portulaca,eleusine, digitaria and various grassy weeds, while'the rice Theapplication of the end product of Example 3 at therate of 0.5 kg/hectareto abarley field before emergence produced a eradication of alopecurus;the compatibility rate was greater than 4 kg/hectare.

For effective control of amaranth and veronica, a rate of application of0.8 kg/hectare of the end product of Example 4 was required.

The end product of Example 5, when applied to a beet field beforeemergence, was very effective for controlling alopeeurus, echinocloa andgalium. but was compatible with the beet plants.

Finally, the end product of Example 8 proved to be effective for thecontrol of grassy weeds at a rate of application of 4 kg/heetare, whilebeing completely com patible with the useful plants.

For agricultural herbicidal purposes the compounds of the presentinvention are incorporated as active ingredients into conventionalagricultural herbicidal compositions, such as emulsions, solutions,suspensions, dusting powders, granulates or the like. The activeingredient concentration in these compositions may vary between about0.05 and 95% by weight, preferably up to about 70% by weight.

Most advantageously, the compounds of the present invention areformulated into concentrate compositions, such as emulsion concentratesor Wettable powders, which can be diluted with water to the desiredapplication concentration, that is, to an active ingredientconcentration of 0.05 to 3% by weight. before use.

The following examples illustrate a few agricultural herbicidalcompositions comprising a compound of the present invention as an activeingredient and represent the best modes contemplated of putting theinvention into practical use. The parts are parts by weight unlessotherwise specified.

EXAMPLE l0 Emulsion Concentrate The concentrate is compounded from thefollowing ingredients:

S-( N-Mcthyl-N-phenyl-carhomoylmethyl)O-ethyl-chloromcthyldithiophosphonate Solvent (mixture of liquidaromatic hydrocarbons) Emulsifier (mixture of alkylaryl sulfonatc andpolyoxycthylene triglyceride) 44 parts Preparation EXAMPLE 1 l WettablePowder The powder is compounded from the following ingredients:

S-(N-Methyl-N-phenyl'carbamoylmethyl)O-methyl-chloromethyldithiophosphonate 50 parts Emulsifier (sodiumlignin sulfonate) 9 Wetting agent (sodium naphthalene sulfonate) lSilicic acid 40 Preparation The ingredients are admixed with each other,and the mixture is milled into a fine powdere. Prior to use, the powderis suspended in a sufficient amount of water to make the activeingredient concentration in the aqueous suspension between 0.05 and 3%by weight. The suspension is a spray composition with effective herbicidal action.

Analogous results are obtained when any one of the other compoundsembraced by formula I is substituted for the particular activeingredient in Examples 10 and l 1. Likewise, the amount of activeingredient in these illustrative examples may be varied to achieve theconcentration range set forth above, and the amounts and nature of theinert carrier ingredients may be varied to meet particular requirements.

While the present invention has been illustrated with the aid of certainspecific embodiments thereof, it will be readily apparent to othersskilled in the art that the invention is not limited to these particularembodiments, and that various changes and modifications may be madewithout departing from the spirit of the invention or the scope of theappended claims.

We claim:

1. A compound of the formula ClCH.

wherein R is alkyl of l to 4 carbon atoms. and

X is oxygen or sulfur.

2. The compound of claim-,1 which is S-( N-methyl-N-phenyl-carbamoylmethyl) O-ethyl-chloromethyldithiophosphonate.

3. The compound of claim 1 which is S-(N-methyl-N-phenyl-carbamoylmethyl) O,-n-butyl-chloromethyl-thiophosphonate.

4. The compound of claim.] which is S(N-methyl-N-phenyl-carbamoylmethyl) O-methyl-chloromethyldithiophosphonate.

5. The compound of claimtl which is S( N-methyl-N-phenyl-earbamoylmethyl) O-nbutyl-chloromethyldithiophosphonate.

6. The compound of claim 1 which is S-(N-methyl-N-phenyl-carbamoylmethyl) O-isopropyl-ehloromethyldithiophosphonate.

7. The compound of claim 1 which is S-(N-methyl-N-phenyl-carbamoylmethyl) O-n-propyl-chloromethyldithiophosphonate.

8. The compound of claim 1 which is S-( N-methyl-N-phenyl-carbamoylmethyl) O-ethyl-chloromethyl-thiophosponate. it

9. The compound of claim 1 which is S-(N-methyl-N-phenyl-carbamoylmethyl O-see.butyl-chloromethylthiophosphonate.

10. The compound of claim 1 which is S-(N-methyl-N-phenyl-carbamoylmethyl) O-isobutyl-ehloromethylthiophosphonate.

1. A COMPOUND OF THE FORMULA
 2. The compound of claim 1 which isS-(N-methyl-N-phenyl-carbamoylmethyl)O-ethyl-chloromethyl-dithiophosphonate.
 3. The compound of claim 1 whichis S-(N-methyl-N-phenyl-carbamoylmethyl)O-n-butyl-chloromethyl-thiophosphonate.
 4. The compound of claim 1 whichis S-(N-methyl-N-phenyl-carbamoylmethyl)O-methyl-chloromethyl-dithiophosphonate.
 5. The compound of claim 1which is S-(N-methyl-N-phenyl-carbamoylmethyl)O-n-butyl-chloromethyl-dithiophosphonate.
 6. The compound of claim 1which is S-(N-methyl-N-phenyl-carbamoylmethyl)O-isopropyl-chloromethyl-dithiophosphonate.
 7. The compound of claim 1which is S-(N-methyl-N-phenyl-carbamoylmethyl)O-n-propyl-chloromethyl-dithiophosphonate.
 8. The compound of claim 1which is S-(N-methyl-N-phenyl-carbamoylmethyl)O-ethyl-chloromethyl-thiophosponate.
 9. The compound of claim 1 which isS-(N-methyl-N-phenyl-carbamoylmethyl)O-sec.butyl-chloromethyl-thiophosphonate.
 10. The compound of claim 1which is S-(N-methyl-N-phenyl-carbamoylmethyl)O-isobutyl-chloromethyl-thiophosphonate.